Cleaning Iron Stone coating off gold

G'day To All Forum Users,

Just a question regarding Hydrochloric Acid and cleaning Iron Stone coating off your gold nuggets.

I have managed to find another little piece today and it is the second of my finds to have a coating of ironstone.

In a previous post, I was told about Hydrochloric Acid to do the job - which I have duly purchased from Bunnings.

My question is this - What type of container or vessel does one use when soaking your nuggets in hydrochloric acid and for how long?

Cheers, Trev

trev. I use any plastic container in a well ventilated area. the fumes are very corrosive to any steel. I have seen the results of nuggets in hydrochloric acid put in a garden shed. one very rusty shed.

tricky 1 wrote:trev. I use any plastic container in a well ventilated area. the fumes are very corrosive to any steel. I have seen the results of nuggets in hydrochloric acid put in a garden shed. one very rusty shed.

G'day Tricky, thanks for that.

Is there a particular grade of plastic required or will any robust style of plastic container do.

How would an average pill/tablet container go for example? And if so, would you do with the lid on or off?

And I know it is like how long is a piece of string, but for how long would you soak or does it depend on the size, shape and amount of ironstone coating?

Cheers Trev

G'day Trev,

As tricky1 has said use a plastic container, I always use one with a good sealing lid and I usually put enough Acid to cover the nuggets properly and leave them soak for a few days. I try to give the container a bit of a shake when I think about it, once or twice a day would be ok.  Once I think the nuggets have had long enough I tip the Acid into another container then rinse the remaining Acid under cold water and leave about half full of water then add 2 tea spoons of baking soda powder to the water with the nuggets inside, this will neutralise any remaining Acid on the nuggets. I usually let it sit until it stops fizzing, probably about 10 mins. Then I will rinse the baking soda/water and then add some dish washing liquid to clean water and give it a good shake for about ten mins the more nuggets the better.     They make each other shiny.
Hope this helps and don't forget your safety procedure.

Cheers.

Mike.

Mike54 wrote:G'day Trev,

As tricky1 has said use a plastic container, I always use one with a good sealing lid and I usually put enough Acid to cover the nuggets properly and leave them soak for a few days. I try to give the container a bit of a shake when I think about it, once or twice a day would be ok.  Once I think the nuggets have had long enough I tip the Acid into another container then rinse the remaining Acid under cold water and leave about half full of water then add 2 tea spoons of baking soda powder to the water with the nuggets inside, this will neutralise any remaining Acid on the nuggets. I usually let it sit until it stops fizzing, probably about 10 mins. Then I will rinse the baking soda/water and then add some dish washing liquid to clean water and give it a good shake for about ten mins the more nuggets the better.     They make each other shiny.
Hope this helps and don't forget your safety procedure.

Cheers.

Mike.

G'day Mike, thanks for that info.

What type of plastic container would you recommend using.....is a vitamin tablet type container suitable/large enough???

I have downloaded a Material Safety Data Sheet for the Acid and have purchased some long acid gloves today and will be wearing safety goggles and treating the product with the respect it deserves.

Every little bit of info helps.....so thanks again for that.

Oh, I will try and follow your tip about the more nuggets the better......just have to get the gold to co-operate with the plan.

Cheers, Trev

G'day Trev,

The container that I am currently using is a clear plastic one that had fruit in, but I have used the vitamin ones that you mentioned and they are fine. The clear one I find I can see how the nuggets are going, but the Acid does get a bit discoloured after a while. Which does make it a little hard to see the nuggets. As you said any plastic container should be fine.

PS the size of the container depends on size/amount of nuggets that go into said container.

Cheers.

Mike.

Mike54 wrote:G'day Trev,

The container that I am currently using is a clear plastic one that had fruit in, but I have used the vitamin ones that you mentioned and they are fine.  The clear one I find I can see how the nuggets are going, but the Acid does get a bit discoloured after a while.     Which does make it a little hard to see the nuggets.  As you said any plastic container should be fine.  

PS the size of the container depends on size/amount of nuggets that go into said container.  

Cheers.  

Mike.  

G'day again Mike, thanks for that update, I can now get onto to it......was thinking perhaps it may require some special grade plastic - I have several suitable types - size dependant......sadly at the present, they won't need to be too large, more's the pity  
I am looking forward to seeing my "monsters" in their natural state though.....all a gleamin'
Cheers, Trev

get yourself a flame proof dish of some sort (chemical beaker)and boil the acid this gets the job done a lot quicker. just stay well away from the fumes and do it in a well ventilated place.

hoolahoopa wrote:get yourself a flame proof dish of some sort (chemical beaker)and boil the acid this gets the job done a lot quicker. just stay well away from the fumes and do it in a well ventilated place.

G'day Hoolahoopa, thanks for your response/input.

I am not sure if I am comfortable doing the full science lab technique though, not exactly fitted or kitted out for that.
Think I will just do the simple soak technique for the moment and who knows if I find a piece that it too large to fit into a plastic container one day I may take up your suggestion. My finds to date sadly do not fall into that category.
Cheers, Trev

Old plastic tablet bottle with the safety kidproof type lid, drop gold in and fill to just above the gold
wait a coupla days and rinse er out.
pinch of brickies sand with the acid also works well with a gentle tumble now n then.

Pete

CrazyPete wrote:
Old plastic tablet bottle with the safety kidproof type lid, drop gold in and fill to just above the gold
wait a coupla days and rinse er out.
pinch of brickies sand with the acid also works well with a gentle tumble now n then.

Pete

G'day Pete, thanks for that response/info.

With the info that forum members have given me, I now have the knowledge on how to go about it.

Hydrochloric Acid is certainly a hazardous material which needs to be respected and used correctly......so thankyou to all who have responded and given me a heads up on the process.

Cheers, Trev

KI tipped all my species in hydrochloric acid (20 nuggets with quartz) for 2 weeks and the quartz was still there, only a few small ones had dissolved. I used the etching stuff for concrete from masters, diggers I think it was? Anyway I was disappointed with it so I wouldn't recommend using it again.

cabletie if you want to get rid of quartz you need to be using hydrofluoric acid not hydrochloric acid.
be real careful with the stuff it will bite if you don't know how to be safe with it.